mdfdsc300

I've got a '92 with new factory stock spark plugs, wires, and distributor put on about 5k miles ago. I am wondering if I should also replace the original ignition coil since it is 10 years old with 78k miles on it. My car just started to stumble and almost die once in a while while idling with the gear in Drive. No codes though. Could it be my coil? Could it be my mass airflow sensor?
If so, what are my choices to replace the stock coil? I have heard that I should stick with the factory coil if I were to replace it. I have also heard to look into alternatives. Advice from someone who's looked into this please!
thanx in advance!

awj

Check the resistances off the primary and secondary according the lexus factory manual. As long as it ohms out correctly - it is fine. The stock ignition is completely adequate in applications up to 800+ hp. There is no need to upgrade.

SC300T

I guess that's why the boosted guys go with an MSD box?

N/A HP gains would be minimal, but an aftermarket ignition like a MSD 6AL could (does) make the car idle and run smoother.

I also picked up some ponies with the 6BTM box, but N/A ppl probably won't notice a difference.

Sounds like stalling rough/ running may be air/fuel related, if the new plugs didn't cure the problem. Timing advance can alter (raise) the idle speed, and the MSD box makes my car idle a little higher.

Lex Luthor

Sure, I know plenty of 800+ hp Soarers running bone stock ignitions.....

awj

I was just qouting what I read from the site on that supra shop in texas. PHR? or whatever. It makes sense - unless you wan't to retard your timing in high boost apps. - of course msd boxes and coil get more spark and allow timing control but ecu piggy backs created for application will allow timing options also. I haven't seen these cars personally so I probably shouldn't comment. Once I get this one set-up, I'll report my experiences.

SC300TURBO

iTrader: (2)

on forced induction the MSD boxes work well smoothing out idle and helping more spark in the top of the rPM range..like SC300T said...i have the stock coil with 127k on it...mabye i should think about replacement....but for now it works great...Jeff

awj

Jeff,
With all that boost and stuff - do you have a stock ecu, or is there a piggy bag unit or replacement "chip".
vpc - vane pressure converter
what is vane pressure and where is it at?
gcc?

AJ

Edit:

emm hmm:
Since this SC is so heavily modified and daily driven, Jeff relies on a bevy of engine management electronics manufactured by HKS and GReddy to maintain drivability. Renowned Toyota tuner extraordinaire Toyomoto also massaged the factory ECM with new fuel and spark curves as well as an extended rev limit. An HKS Vein Pressure Converter (VPC) converts the mass-air based stock engine management over to speed-density, controlling the larger 440 cc/min primary fuel injectors and is fine-tuned by an HKS Graphic Control Computer (GCC). Once the 440 cc injectors run out of breath, a GReddy Rebic IV fires up a duo of 550 cc auxiliary injectors to quench the fire under high boost. A GReddy PRofec B handles boost control and the turbo timer is a classic GReddy unit. Engine vitals are monitored with Autometer boost and air/fuel ratio gauges.

Is this your car?